Gov. Mike Pence is dropping his re-election bid in Indiana to become Donald Trump’s running mate.

IndyStar confirmed shortly after noon Thursday that Trump is planning to announce Pence as his selection for vice president. Several national news outlets, including CNN and ABC News, later reported Trump had offered the post to Pence and he had accepted, ending a weekslong casting call during which Trump vetted a handful of high-profile Republicans.

Trump had been scheduled to formally announce his pick at a news conference in Manhattan at 11 a.m. Friday, but delayed the event in the wake of an attack in Nice, France, that left more than 70 people dead.

The delay could leave Pence, who had already traveled to New York, in political limbo. He faces a noon Friday deadline to withdraw from the governor's race to allow Indiana Republican leaders to select a replacement candidate.

The developments capped another wild day in the vice presidential search, with Trump's campaign team insisting throughout the day that no decision had been made, even as Pence was being whisked toward Manhattan in a motorcade after flying on a private plane from Indianapolis to Teterboro, N.J.

In a Thursday evening interview with Fox News, Trump said he still hadn't made a "final, final" decision. It wasn't clear if those comments were meant to maintain a sense of surprise for the planned announcement, but Republican strategists, including a former Trump adviser, have repeatedly emphasized Trump's unpredictability and noted anything is possible.

Trump's long-awaited decision upends the political landscape in Indiana and at least partially remakes the Trump campaign.

In Pence, Trump adds a social conservative whom GOP strategists say will reassure rank-and-file Republicans that Trump can be trusted to pursue their interests. Veteran political observers say Pence, a former U.S. House member and chairman of the House Republican Conference, will provide a disciplined counter to Trump’s improvisational campaign style. Pence also brings fundraising power and credibility on a wide range of policy issues that are important to conservatives.

Pence would officially become the vice presidential nominee during the Republican National Convention, which starts July 18 in Cleveland. He could become the first vice president from Indiana since Dan Quayle took office in 1989 under George H.W. Bush.

Pence’s departure for national politics sets up a scramble among Indiana Republicans to determine who will replace Pence to run against Democratic challenger John Gregg in the November gubernatorial election.

For the first time in state history, the Indiana Republican State Committee will determine the GOP candidate for governor in a process that could last into August. The 22-member panel has 30 days to choose Pence’s replacement on the ballot. Once it’s clear who will be vying for the Republican nomination, the committee must provide a 10-day notice before it votes. That means, at the earliest, the process will conclude in late July.

Lt. Gov. Eric Holcomb, who has not yet publicly said he will seek the office, is thought to be a front-runner. U.S. Rep. Susan Brooks of Carmel plans to withdraw from her congressional race and run for governor, said Murray Clark, a former state Republican Party chairman and a partner at the law firm Faegre Baker Daniels. U.S. Rep. Todd Rokita has said he plans to run.

First, though, Pence must file paperwork to withdraw his name from the ballot. While the deadline to do that is noon Friday, Pence could withdraw, then ask the state's GOP central committee to renominate him if he doesn't get the vice presidential nomination.

Pence's elevation in the political world comes as he faced a tight race in Indiana. The most recent public poll, which was conducted in May, showed Pence leading Gregg 40 percent to 36 percent, a virtual tie when factoring in the 4 percent margin of error. Pence defeated Gregg in the 2012 race by 3 percentage points.

Pence, a vocal Trump supporter since he clinched the Republican nomination, will turn his attention toward helping the real estate mogul defeat Democrat Hillary Clinton in November. Even without Pence, Trump has been closing the gap. A national CBS News/New York Times poll released this week shows Clinton and Trump tied at 40 percent just one month after Clinton had a 6 percentage point lead. Yet, projections based on state polls suggest Clinton has an advantage, albeit a diminishing one.

Trump appeared to have winnowed the field of potential running mates from about 10 people last week in a fashion that some have compared to a reality-TV show, complete with auditionlike campaign appearances. Aside from Pence, the other favorites were former House Speaker Newt Gingrich and New Jersey Gov. Chris Christie.

Pence essentially tried out for the position during a Trump rally in Westfield and a fundraiser in Indianapolis on Tuesday. Pence, who has traditionally eschewed negative campaigning, used the rally to attack Clinton for the loss of U.S. personnel in Benghazi, Libya, and compare Trump to Ronald Reagan.

Speculation that Trump would pick Pence intensified after Trump and his family unexpectedly dined with Pence and his wife at a swanky Downtown restaurant Tuesday night, then had breakfast at the governor's residence the next morning.

Governor Mike Pence puts on his helmet as First Lady Karen Pence, right, waits to get on the motorcycle before starting the Miracle Ride, Sunday, June 5, 2016. The annual event raises money for Riley Hospital for Childrenat IU Health. Kelly Wilkinson/IndyStar

Governor Mike Pence and his family moved into the Governor's residence Saturday, February 2, 2013. In this photo, Governor Pence opens a box as his wife, Karen, and his daughter, Audrey, look on, in his home office. Kelly Wilkinson / The Star Kelly Wilkinson, Indianapolis Star

Governor Mike Pence and his family moved into the Governor's residence Saturday, February 2, 2013. In this photo, Governor Pence moves in a box. Kelly Wilkinson / The Star Kelly Wilkinson, Indianapolis Star

Governor-elect Mike Pence and his wife, Karen, danced to the music of The Impalas at the Pence-Ellspermann Inaugural Ball Dinner and Dance at the J.W. Marriott in Indianapolis on Jan. 12, 2013. Joe Vitti/IndyStar 2013 file photo

Governor-elect Mike Pence and wife Karen applaud after dancing to the song "Easy" by The Commodores performed by The Impalas at the Pence-Ellspermann Inaugural Ball Dinner and Dance at the JW Marriott Saturday January 12, 2013.. Joe Vitti / The Star Joe Vitti, Indianapolis Star

Gov.-elect Mike Pence and his wife Karen and son Michael leave their home in McCordsville for the ride to Indianapolis where he will become Indiana's 50th governor at an 11 a.m. inauguration ceremony at the Indiana Statehouse on Monday, January 14, 2013. Charlie Nye / The Star. Charlie Nye, Indianapolis Star

Gov. Mike Pence and his wife embrace behind the desk in his new office at the Indiana Statehouse as their children Charlotte, Michael and Audrey (not shown) stand next to the, following Pence's inaugural ceremony on Monday morning, January 14, 2013. Pence is Indiana's 50th governor. Charlie Nye / The Star. Charlie Nye, Indianapolis Star

Gov. Mike Pence and his family, from left, daughter Charlotte, wife Karen, son Michael and daughter Audrey, pose for a photo around his desk in the Governor's office following his inauguration as Indiana's 50th governor on Monday, January 14, 2013. Charlie Nye / The Star. Charlie Nye, Indianapolis Star

First Lady of Indiana Karen Pence shows off her new Indiana bicentennial necklace during the 1816 Commemorative Forever Stamp First-Day-Of-Issue Stamp Dedication Ceremony, celebrating Indiana's Bicentennial, held at the Indiana Statehouse, Tuesday June 7th, 2016. The photograph appearing on the stamp was taken by Michael Matti and designed by Derry Noyes. Michelle Pemberton / Indy Star

First Lady Karen Pence and Governor Mike Pence walk away with their new brooms after meeting with Jim Richter, the "Broom Guy," at one of the typical spots where he sells his brooms, at 71st and College, Tuesday, April 5, 2016. The Pences met with Richter to buy brooms and offer encouragement after he recently was thrown off the property at a local post office where he also sold his brooms. The Governor said he is reaching out to the Post Master General to address the situation. Kelly Wilkinson/IndyStar

First Lady Karen Pence and Governor Mike Pence meet with Jim Richter, the "Broom Guy," at one of the typical spots where he sells his brooms, at 71st and College, Tuesday, April 5, 2016. The Pences met with Richter to buy brooms and offer encouragement after he recently was thrown off the property at a local post office where he also sold his brooms. The Governor said he is reaching out to the Post Master General to address the situation. Kelly Wilkinson/IndyStar

The Governor's residence is ready for the holiday season. Colors of blue and gold highlight most of the decorations to celebrate Indiana's bicentennial. First Lady Karen Pence gives a tour of the many decoration in the Governor's residence at 4750 N. Meridian Street. This tree was donated by Hillcrest Tree Farm in Greenfield. Matt Kryger/The Star

Indiana first lady Karen Pence (shown in her office) hosted her First Lady’s Luncheon Thursday. At the fundraiser for her foundation, $65,000 was awarded to Feeding Indiana’s Hungry. Charlie Nye / The Star

Indiana Governor Mike Pence and first lady Karen, along with Garfield creator Jim Davis welcomed trick-or-treaters to the governor mansion Friday, October 31, 2014, evening in the north side of Indianapolis. Here Isabela and Abigail Ahn greet Governor Beekeeper and his Bee. Matt Kryger / The Star

State Treasurer Richard Mourdock, left, speaks with Rep. Mike Pence and his wife Karen Pence before the Congressman takes the stage at the Indianapolis Tea Party get-out-the-vote rally held in Hummel Park in Plainfield on Friday night, October 15, 2010. Charlie Nye / The Star. Charlie Nye